The BrÃ¼nnich’s Guillemot, or Thick-billed Murre (Uria lomvia) is a bird in the auk family that breeds on coasts and islands in the high Arctic of Europe, Asia and North America. It is one of the most numerous birds in the high arctic.
These birds breed in large colonies located high atop coastal cliffs. They lay a single egg directly on a cliff ledge. They migrate south in winter into the northernmost areas of the north Atlantic and Pacific, but only to stay in ice-free waters. The larger size of this species makes it less prone than the Little Auk to be carried further south by late autumn storms, and they are consequently rare in temperate latitudes.
This species is only marginally larger than the closely related Common Guillemot, measuring 40-44 cm in length and with a wingspan of 64-75 cm.
Adult birds are black on the head, neck, back and wings with white underparts. The bill is long and pointed. They have a small rounded black tail. The lower face becomes white in winter. They differ from Common Guillemot in their thicker bill, darker back and white gape stripe. In winter, there is less white on the face.
The BrÃ¼nnich’s Guillemot’s flight is strong and direct, using their short wings for faster wing beats. They look shorter than Common Guillemot in flight. These birds forage for food like other auks, by swimming underwater. They mainly eat fish, also some crustaceans and other small invertebrates.
This species produces a variety of harsh cackling calls at the breeding colonies, but is silent at sea.
This bird is named after the Danish zoologist Morten Thrane BrÃ¼nnich.
Threats: Important threats in Newfoundland and Greenland include intensive egg harvesting and hunting of adult birds. In the Barentsee it is now reduced to local influences associated to polar stations in Russia. Fisheries may be a threat, but due to their ability to utilize alternative food sources the effect of over-fishing is not as much as on the common guillemots. Pollution of oil and gas exploitation exerts a serious threat. It’s one of the seabirds most sensitive to these influences. Gas condensate and oil deposit can be of great harm. Incidental mortality in fishing gear is also important (Vidar Bakken, Irina V. Pokrovskaya, 2000).
Status in Europe south of the breeding range
BrÃ¼nnich’s Guillemot is a rare vagrant in European countries south of the breeding range. In Britain, over 30 individuals have been recorded, but over half of these were tideline corpses. Of those that were seen alive, only three have remained long enough to be seen by large numbers of observers. All three were in Shetland – winter individuals in February 1987 and November/December 2005, and a bird in an auk colony in summer 1989 (the 1989 and 2005 birds were both found by the same observer, Martin Heubeck).
BrÃ¼nnich’s Guillemot has been recorded once in Ireland, and has also been recorded in The Netherlands.